RESEARCH

Current Projects

My consulting work continues to be focused on coastal systems in British Columbia, Canada, where I  can leverage my deep knowledge of this region to understanding species distributions, the classification of marine systems, and the services they provide to people.

With colleagues at Fisheries and Oceans Canada, we produced a framework for rapid production of species distribution models to support marine spatial planning. We are now working on producing defensible, high-resolution classification of bottom type – a predictor layer that is critical for coastal systems.

Refining our recent work on sea otter-fisheries interactions in coastal British Columbia, I am now exploring how the costs and benefits are distributed across the coast. There are encouraging signs that spatial management strategies may improve the co-existence of sea otters and humans along the coast.

I continue to work on a trans-disciplinary effort with colleagues from Academia, Fisheries and Oceans Canada, and communities on the effective characterization of cumulative impacts on valued species.

Latest Publications

My academic work focused in part on how the changes in resource distribution caused by an expanding sea otter population influence the ecosystem services provided to people. This work combined models of kelp forests, sea otter populations, and trophic interactions to explore trade-offs among between different sea otter management alternatives. This of course begs the question of how much confidence we should have in the models that we develop - a question I never stop asking.

Some of the above work is represented in the following publications.

Gregr, E.J., V. Christensen, L. Nichol, R. Martone, R. Markel, J.C. Watson, C.D.G. Harley, E.A. Pakhomov, J.B. Shurin, and K.M.A. Chan. 2020. Cascading social-ecological costs and benefits triggered by a recovering keystone predator. Science. DOI:science.sciencemag.org/cgi/doi/10.1126/science.aay5342.

This synthetic analysis combined ecology and economic analysis in a social-ecological model of the West Coast of Vancouver Island, where recovering sea otters are transforming the coastal ecosystem by reducing populations of benthic invertebrates and releasing kelp forests from grazing pressure. While the recovering sea otters threaten established shellfish fisheries, our results suggest that sea otter presence will result in 37% more ecosystem biomass annually, increasing the value of finfish by 9.4M CA$, and providing 2.2M CA$ in carbon sequestration. Otter presence will also boost ecotourism by as much as 42M CA$ a year. If fully realized, these benefits will well exceed the annual loss to invertebrate fisheries (-$7.3M CA$).

However, these costs and benefits will not be equitably distributed and non-monetary costs, in particular the loss of subsistence harvest to remote coastal communities, are also real and potentially catastrophic in light of already exploited finfish stocks. The equity of potential management alternatives will be explored in a follow-up publication on local sea otter management.

Gregr, E.J. and K.M.A. Chan 2015. Leaps of Faith: How implicit assumptions compromise the utility of ecosystem models for decision-making. Bioscience 65(1): 43-54.

All models have assumptions. But not all assumptions are equal, and different assumptions are appropriate in different contexts, and for different questions. In this review, we show that uncertainties and design assumptions are mostly ignored in the popular modelling literature, illustrate the importance of model assumptions in assessing model uncertainty, and offer a conceptual model to support more consistent model design decisions.

The editor liked the article so much he wrote an editorial entitled ‘Models are not Toys’, where he called our results “shocking”. You can read the full editorial here https://academic.oup.com/bioscience/article/65/1/3/379449.

Gregr, E.J., D.M. Palacios, A. Thompson, and K.M.A. Chan, 2019. Why less complexity produces better forecasts: an independent data evaluation of kelp habitat models. Ecography, 42(3), pp.428-443.

This work asks why habitat suitability models continue to see limited use in resource management, and addresses the question of vague model objectives and inadequate evaluation methods using habitat models for canopy kelps (Macrocystis pyrifera and Nereocystis luetkeana). We examined a series of increasingly complex habitat suitability models looking for limits to model complexity, and to explore the relationship between model complexity and forecast skill.

In addition to confirming the importance of established predictors of coastal kelp distributions (i.e. depth, bottom type, bottom slope, and exposure), we also identified additional factors including salinity, and interactions between exposure and salinity, and slope and tidal energy.

Methodologically, we showed how cross‐validation can lead to over‐fitting, and how independent data evaluation can identify the appropriate model complexity for generating habitat forecasts. Our results also show that predictions from simpler models can out‐perform those from more complex models. The continued development of methods and metrics for evaluating model forecasts with independent data, and the explicit consideration of model objectives and assumptions, promise to increase the utility of model forecasts to decision makers.

Davies, S.C., E.J. Gregr, J. Lessard, P. Bartier, and P. Wills. 2019. Coastal digital elevation models integrating ocean bathymetry and land topography for marine ecological analyses in Pacific Canadian waters. Can. Tech. Rep. Fish. Aquat. Sci. 3321: vi + 38 p.

Accurate predictors are essential to credible maps of species distributions. We developed a series of five 20 m coastal digital elevation models (DEMs) for Canada's Pacific region to support spatial analysis, specifically for the nearshore domain, extending from the high intertidal to 50 m depth. These bathymetric products are at a higher resolution and greater extent in shallow waters than previously available DEMs for the area. They provide a critical foundational layer for modelling species, habitats, and environmental variables across Canada's Pacific region and will benefit marine spatial planning initiatives such as Marine Protected Areas and oil spill response strategies.

Nephin, J., E.J. Gregr, C. St. Germain, C. Fields, and J.L. Finney. 2020. Development of a Species Distribution Modelling Framework and its Application to Twelve Species on Canada’s Pacific Coast. DFO Can. Sci. Advis. Sec. Res. Doc. 2020/004. xii + 107 p.

Species distribution models (SDMs) are a valuable tool for the management and conservation of marine resources and places. In this work we address critical aspects of SDM development and uncertainty assessment that are routinely overlooked. This framework was prepared as both a tool and a set of guidelines and methods for the development of consistent, interpretable, and defensible SDMs to support DFO’s contribution to Canada's ocean policies.

SDMs were built for twelve benthic species to illustrate the application of the framework, and contribute to emergency oil spill response planning in Pacific Canada. We built three models of increasing complexity using a suite of best available environmental predictors. Knowledge-based envelope models were produced for all species, and emphasized for those found to be data deficient. These models can be used to evaluate uncertainty in model predictions, and provide an avenue for engaging First Nations and species experts in the process. Data-driven generalized linear (GLM) and boosted regression tree (BRT) models were generated, along with a corresponding ensemble model, for the eight species found to have adequate observational data.

Thirteen recommendations were conceived as part of the development of the framework and its application to provide guidance on the application of SDM methods related to data selection and preparation, model development and evaluation. Development of SDMs for additional species in Pacific Canada will be greatly facilitated by the set of common predictors, methods, and evaluation tools assembled here.

Full Publication List

Historic Project List

Representing nearshore ecosystems in Pacific Canada (2014-2016)
Fisheries and Oceans Canada, Nanaimo, British Columbia

As part of Fisheries and Oceans World Class oil spill response initiative, applied the methods developed for the Strait of Georgia (Gregr et al. 2013a) to all Pacific Canadian nearshore (0 to 50 m depth) waters. The resulting data products include 20 m bathymetric models, a seamless representation of bottom type, and tidal and wind-wave energy models.

Advancing the role of social science in the North Pacific Research Board’s research program (2014)
North Pacific Research Board, Anchorage, Alaska

Convened a workshop to consult with social scientists about the challenges facing the integration of natural and social sciences within the NPRB's research program. We found the challenges grouped into four themes: Leadership, Practice, Communication, and Understanding. The resulting report now forms part of the NPRB's science integration strategy.

Foraging habitat of the Leatherback Sea Turtle (Dermochelys coriacea) in Pacific Canadian waters (2012)
Fisheries and Oceans Canada, Vancouver, British Columbia

Using the best available information on Leatherback habitat use, and foraging habits, developed an envelope model to represent potential foraging habitat in Pacific Canadian waters to inform the Species At Risk critical habitat designation. Characteristic features included depth, chlorophyll-a concentrations, and ocean currents.

A spatial framework for representing nearshore ecosystems (2009-2012)
Marine Ecosystems and Aquaculture, Fisheries and Oceans Canada, Nanaimo, British Columbia

Developed a method for integrating diverse data sets into a seamless map of nearshore bottom type, a key indicator of benthic habitat. This work is central to understanding species distributions and anthropogenic risk. The spatial framework allows a diversity of other data to be attached, leading to a comprehensive characterization of the nearshore ecosystem.

Defining EBSAs in the eastern North Pacific (2009-2011)
Marine Ecosystems and Aquaculture, Fisheries and Oceans Canada, Nanaimo, British Columbia

Developed an approach for Vulnerable Marine Ecosystems (VMEs) identification in Pacific Canadian waters and the oceanic Northeast Pacific based on the review of previously applied methods for identifying ecologically and biological sensitive marine areas (EBSAs) in Canadian waters.

Right whale (Eubalaena japonica) habitat in the North Pacific and Bering Sea (2006-2010)
North Pacific Research Board, Anchorage, Alaska

Grant awarded to SciTech Environmental Consulting to investigate the distribution of historic right whale sightings and develop several, multi-scale models of potential foraging habitat in the North Pacific. The study included research in right whale ecology, plankton ecology, and physical oceanography.

Steller Sea Lion – Fisheries Competition Study (2002-2008)
Marine Mammal Research Unit, Fisheries Centre, University of British Columbia, Vancouver, British Columbia

Led investigations into the habitat of Steller sea lions and the potential for competition with commercial fisheries. The study included the development of a predictive model of Steller sea lion habitat; a review of prey distributions and the development of potential prey fields; quantification of the overlap between commercial fisheries and Steller sea lion habitat; and an assessment of the efficacy of fisheries regulations designed at reducing this overlap.

Benthic Classification of the northern British Columbia shelf (2005-2007)
NRCan and Fisheries and Oceans Canada

Assembled and derived the necessary data sets for a benthic classification of the Pacific North Coast Integrated Management Area in Pacific Canadian waters. Investigated the utility of available data sets, and proposed and implemented algorithms to classify the region according to Disturbance and Adversity characteristics.

Abalone Habitat Modelling (2004)
Marine Environmental Quality Section, Fisheries and Oceans Canada, Nanaimo, British Columbia

Using the B.C. shorezone units, the B.C. ecounits classification, and other appropriate data sets, predicted high suitability areas for northern abalone throughout British Columbia.

Statistical Methods for Fish Habitat Characterization (2003)
Aquatics Information Branch, Ministry of Sustainable Resource Management, Victoria, British Columbia

Evaluated alternative methods to describe species-habitat relationships relating freshwater species in British Columbia to landscape (1:50,000) and stream (1:20,000) characteristics. The study reviewed statistical methods relating to ordination, regression and Bayesian methods to combine analyses at different resolutions and incorporating different data sets.

Marine Mammals in the Hecate Strait Ecosystem (2003)
Hecate Strait Ecosystem Project, Fisheries and Oceans Canada, Nanaimo, British Columbia

Reviewed the abundance, diet, and habitat use of marine mammals in the waters off British Columbia’s north and central coasts. Includes, to the extent possible, estimates of population trends and exploitation from 1950 to present day, and a review of the ecology of the species in relation to their habitat.

Sea Otter Carrying Capacity Model (2002-2003)
Conservation Biology, Stock Assessment, Fisheries and Oceans Canada, Nanaimo, British Columbia

Developed an estimate of the carrying capacity (maximum population) of the British Columbia coast for sea otters. The analysis included a measure of coastline complexity, a species-habitat relationship, and bootstrapped confidence intervals.

A Framework for Defining Marine Sensitive Areas (2002)
Decision Support Services, Ministry of Sustainable Resource Management, Victoria, British Columbia

Reviewed current approaches and formalized necessary definitions to establish a methodology for defining the spatial boundaries of Marine Sensitive Areas in the coastal waters of British Columbia. The work was intended to form the basis of a quantitative, repeatable, analytic approach to identifying sensitive marine areas for future marine protection.

Status Report of the Sei Whale (2002)
Committee on the Status of Endangered Wildlife in Canada (COSEWIC), Canadian Wildlife Service, Ottawa, ON

Summarized the scientific, community and aboriginal knowledge of the northeastern Pacific and the northwestern Atlantic populations of the sei whale (Balaenoptera borealis).

Monterey County Community Planning Model (1999-2002)
Monterey County, California. Project Manager/Lead Developer

As the decision management solutions consultant for Monterey County, designed and delivered an automated decision framework which analyzes public policy choices for technical and values-based impacts in support of the Community Plan Update process. The Community Planning Model provides tabular, graphical and map based displays of the trade-offs between suites of policies, and includes interactive spatial analysis over the Internet.

HydroBasin Relicensing Planning Framework (1997-1999)
Southern California Edison, California. Lead Developer

Implemented and managed a watershed decisions framework for the integration and optimization of hydroelectric, recreation, and fisheries management policies to balance the values of multiple stakeholders. The model forms the basis of SCE’s approach to watershed management and basin-wide re-licensing.

Historic Whaling Data Analysis and Habitat Modelling (1996-1998)
Marine Mammal Research Unit, University of British Columbia

Designed a habitat analysis integrating spatio-temporal historic whaling data with oceanographic data (depth, temperature, salinity). The analysis described animal distribution patterns and their relationship with oceanographic predictor variables.

Pollution Source Inventory (1995-1996)
Burrard Inlet Environmental Action Program, Environnent Canada. Project Manager/Lead Developer

Designed, researched and constructed the Pollution Source Inventory (database and maps) of point source discharges into Burrard Inlet. Deliverables included an extensive report documenting all point and non-point pollution sources and a geographic information system (GIS) based data management system.

Robson Bight (Michael Bigg) Ecological Reserve Management Program (1992-1995)
BC Parks, Province of British Columbia. Field Supervisor/Project Administrator

BC operates a warden and information program in critical Killer Whale habitat on northern Vancouver Island. Services were operated from a remote field camp opposite the critical habitat area. Participated in warden and public education services, and was responsible for project administration, logistics and staff training.

Custom tools and applications

In collaboration with various colleagues, I have developed a variety of tools to support scientific analyses and data management. These include a series of semi-automated scripts to define bottom type from a diverse collection of source data, a tool to translate herring spawn transects to polygons, a web-based application to display the distribution of tsunami debris in BC linked to aerial photographs, and a stand-alone geo-spatial application to measure fetch given a set of inputs.